Physics(Please help)

A person is riding a bicycle, and its wheels have an angular velocity of 26.0 rad/s. Then, the brakes are applied and the bike is brought to a uniform stop. During braking, the angular displacement of each wheel is 17.6 revolutions. (a) How much time does it take for the bike to come to rest? (b) What is the anguar acceleration (in rad/s2) of each wheel?

Do I need to convert revolutions to radians first?

Physics(Please respond) - Elena, Tuesday, June 5, 2012 at 11:31am
Equations for decelerated motion are
ù=ùₒ - å•t,
ö = ùₒ•t - å•t²/2.

Since ù =0, ö = 2•ð•N, where N =17.6 rev.
these equatuions are
0=ùₒ-å•t, …………………… (1)
2•ð•N = ùₒ•t - å•t²/2 …………(2)
From (1)
å = ùₒ/t……………………… (3)
Plug it in (2) and obtain
t= 4•ð•N/ ùₒ.
Then determine angular acceleration using (3).

so first I have to do equation 2? So
2*pi*17.6 = I am not sure what wo is. Would it be the 26.0?

  1. 👍 0
  2. 👎 0
  3. 👁 247
  1. ε = ωₒ/t
    (3) ->(2)
    2•π•N = ωₒ•t - ε•t²/2 = ωₒ• t – (ωₒ/t) •t²/2 = ωₒ• t/2,
    t= 4•π•N/ ωₒ =4•π•17.6/26 =8.5 s
    ε = ωₒ/t = 26/8.5=3.06 rad/s²

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Trigonometry

    a bicycle with 24inch diameter wheels is traveling at 15mi/hr. a) Find the angular speed of the wheels in rad/min. b)How many revolutions per minute do the wheels make?

  2. physics

    A bicycle is rolling down a circular portion of a path; this portion of the path has a radius of 8.73 m. As the drawing illustrates, the angular displacement of the bicycle is θ = 0.979 rad. What is the angle (in radians) through

  3. physics

    A 4.50-kg wheel that is 34.5 cm in diameter rotates through an angle of 13.8 rad as it slows down uniformly from 22.0 rad/s to 13.5 rad/s. What is the magnitude of the angular acceleration of the wheel? A) 0.616 rad/s 2 B) 22.5

  4. Physics

    I already figured out the answers to some but I need help with two more. 1) A disk with an initial angular velocity ω0 = 4.5 rad/s experiences a constant angular acceleration of α = 7.5 rad/s2 for time t = 15 s. Please answer

  1. Physics

    Two disks are rotating about the same axis. Disk A has a moment of inertia of 4.53 kg·m2 and an angular velocity of +4.55 rad/s. Disk B is rotating with an angular velocity of -6.86 rad/s. The two disks are then linked together

  2. Physics

    Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 6.00 s, it rotates 28.0 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular

  3. trigonometry

    A truck with 48-in.-diameter wheels is traveling at 45 mi/h. (a) Find the angular speed of the wheels in rad/min. rad/min (b) How many revolutions per minute do the wheels make? rev/min

  4. Physics 1 (Calc Based)

    At t = 0, a wheel rotating about a fixed axis at a constant angular acceleration of –0.40 rad/s^2 has an angular velocity of 1.5 rad/s and an angular position of 2.3 rad. What is the angular position of the wheel at t = 2.0 s?


    A car is traveling along a road, and its engine is turning over with an angular velocity of +199 rad/s. The driver steps on the accelerator, and in a time of 14.2 s the angular velocity increases to +263 rad/s. (a) What would have

  2. physics

    2. At time t =0, the current to the dc motor is reversed, resulting in an angular displacement of the motor shaft given by θ = (198 rad/s)t – (24 rad/s2)t2 – (2 rad/s3)t3 a. At what time is the angular velocity of the motor

  3. Physics

    A bicycle has wheels of radius 0.32 m. Each wheel has a roatational inertia of 0.080 kg•m^2 about its axle. The total mass of the bicycle including the wheels and the rider is 79 kg. When coasting at constant speed, what

  4. Precalculus with trigonometry

    I REALLY NEED HELP WITH THIS Della Casee is riding a racing bike at a speed of 50.4 km/h. the wheels have a diameter of 70 cm. Find the angular velocity of the wheel in radians per second.

You can view more similar questions or ask a new question.